U.S. patent application number 12/844424 was filed with the patent office on 2011-02-03 for sensor element device.
This patent application is currently assigned to E.G.O. Elektro-Geraetebau GmbH. Invention is credited to Holger Dombrowski, Thorsten Fix.
Application Number | 20110025643 12/844424 |
Document ID | / |
Family ID | 43067117 |
Filed Date | 2011-02-03 |
United States Patent
Application |
20110025643 |
Kind Code |
A1 |
Dombrowski; Holger ; et
al. |
February 3, 2011 |
SENSOR ELEMENT DEVICE
Abstract
A sensor element device for a capacitive proximity switch of an
operating device, where the sensor element device has an upper side
for contacting the underside of an operating panel of the operating
device and a block-like illuminated display with a lighting
direction towards the underside of the operating panel. The sensor
element device is electrically conductive on its side or an upper
side facing the operating panel, thereby forming a sensor element.
The illuminated display is mounted on a component carrier by a
voluminous, spatial-shape-variable, elastic and electrically
conductive material, where this material layer provides the
required variable distance and electrical connection from the upper
side to the underside as electrical contacts.
Inventors: |
Dombrowski; Holger;
(Oehringen, DE) ; Fix; Thorsten; (Pforzheim,
DE) |
Correspondence
Address: |
ALSTON & BIRD LLP
BANK OF AMERICA PLAZA, 101 SOUTH TRYON STREET, SUITE 4000
CHARLOTTE
NC
28280-4000
US
|
Assignee: |
E.G.O. Elektro-Geraetebau
GmbH
|
Family ID: |
43067117 |
Appl. No.: |
12/844424 |
Filed: |
July 27, 2010 |
Current U.S.
Class: |
345/174 |
Current CPC
Class: |
H03K 2017/9602 20130101;
H03K 2217/96079 20130101; H03K 17/962 20130101; H03K 2217/96076
20130101 |
Class at
Publication: |
345/174 |
International
Class: |
G06F 3/045 20060101
G06F003/045 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 28, 2009 |
DE |
10 2009 036 162.6 |
Claims
1. A sensor element device for a capacitive proximity switch of an
operating device with an operating panel, said sensor element
device having an upper side for contacting an underside of said
operating panel, said sensor element device comprising: an
illuminated display comprising a sensor element, said illuminated
display having a top side facing said underside of said operating
panel, said illuminated display comprising a frame body with a
lighting direction towards said underside of said operating panel,
wherein said illuminated display is electrically conductive at
least on said top side facing said underside; and a material layer
comprising an elastic, electrically conductive material having a
first side and a second side, wherein said illuminated display is
attached to said first side of said material layer and said second
side of said material layer is attached to a component carrier,
wherein said illuminated display has an electrically conductive
connection from said upper side to said underside for establishing
contact to said material layer, and wherein said illuminated
display is further connected via said material layer to an
electrical port of a control unit.
2. The sensor element device according to claim 1, wherein said
sensor element of said illuminated display is designed in a
surrounding, frame-like manner.
3. The sensor element device according to claim 1, wherein said
sensor element is coincident with said top side of said illuminated
display.
4. The sensor element device according to claim 1, wherein said
sensor element has a recess approximately of a size of a display
symbol of said illuminated display.
5. The sensor element device according to claim 1, wherein said
sensor element is in planar contact with said underside of said
operating panel.
6. The sensor element device according to claim 1, wherein said
electrically conductive connection is a conductive lacquer provided
on said top side of said illuminated display at least in an area of
contact by one part of said sensor element with said underside of
said operating panel and extending from a rim of said illuminated
display to a lower area or to an underside and to said material
layer.
7. The sensor element device according to claim 6, wherein said
conductive lacquer is translucent.
8. The sensor element device according to claim 7, wherein the said
conductive lacquer covers substantially said entire top side of
said illuminated display.
9. The sensor element device according to claim 6, wherein said
conductive lacquer is opaque.
10. The sensor element device according to claim 6, wherein said
conductive lacquer covers a surrounding frame-like area of said
illuminated display.
11. The sensor element device according to claim 1, wherein said
illuminated display comprises at electrically conductive material
forming both said sensor element on said top side of said
illuminated display and said electrically conductive connection on
said material layer.
12. The sensor element device according to claim 11, wherein said
electrically conductive material layer is electrically conductive
plastic.
13. The sensor element device according to claim 1, wherein said
illuminated display or said frame body is designed in a block-like
manner.
14. The sensor element device according to claim 1, wherein said
illuminated display comprises a seven-segment display with a frame
body and light guide bodies of translucent material or light
passageways.
15. The sensor element device according to claim 1, wherein said
illuminated display is fastened to said material layer by an
electrically conductive bond.
16. The sensor element device according to claim 1, wherein said
material layer comprises electrically conductive, flexible
foam.
17. The sensor element device according to claim 1, wherein said
material layer has a cutout for arrangement of an illuminant
therein for said illuminated display.
18. The sensor element device according to claim 17, wherein said
cutout is located centrally and said material layer is designed as
an surrounding frame and in particular opaque to a lateral
side.
19. An illuminated display, comprising: an operating panel having a
top side and a bottom side, said operating panel capable of
transmitting light; a sensor element device having a top side and a
bottom side, said top side of said sensor element positioned to
contact said bottom side of said operating panel, said sensor
element comprising; an electrically conductive material, an
illuminated display, contacting said electrically conductive
material, wherein said electrically conductive material is located
between said operating panel and said illuminated display, said
illuminating display having a light guide allowing passage of said
light, and a material layer comprising electrically conductive,
elastic material, said material layer having an opening allowing
passage of said light; and a component carrier comprising a printed
circuit board contacting said material layer, wherein said
component carrier comprises a contact panel substantially in
contact with said material layer, wherein an electrical contact is
formed from said bottom side of said operating panel to said
contact panel of said printed circuit board, and wherein a
illuminant generates said light.
20. The illuminated display of claim 19 wherein said electrically
conductive material comprises a translucent, electrically
conductive lacquer.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to German Application
Number 10 2009 036 162.6, filed on Jul. 28, 2009, the contents of
which are incorporated by reference for all that it teaches.
FIELD OF THE INVENTION
[0002] The invention relates to a sensor element device for a
capacitive proximity switch of an operating device.
BACKGROUND OF THE INVENTION
[0003] A sensor element device is known from EP 859 467 A (also
published as U.S. Pat. No. 5,917,165), having a voluminous and
spatial-shape-variable plastic body in cylindrical form with a
recess in the longitudinal direction. On its upper side, a plastic
disk having a translucent portion in symbol form, for example as an
elongated rectangle, is provided. An LED provided inside the recess
in the plastic body therefore has the effect of creating an
illuminated symbol display. The upper side of the elastic plastic
body as a wide circular ring forms a capacitive sensor element of
the capacitive proximity switch device.
[0004] It is furthermore known from EP 1 030 536 A1 (also published
as U.S. Pat. No. 6,403,904) how to provide a surrounding metal
frame with an illuminated display as a seven-segment display. This
frame runs supported at the side past the illuminated display and
thereby, as it were, enables a capacitive proximity switch to be
created with an illuminated display. If a finger is placed on the
illuminated display, in particular with an operating panel in
between them, the capacitive proximity switch can detect this and
trigger a switching function.
SUMMARY
[0005] An object underlying the invention is to provide a sensor
element device of the aforementioned type for a capacitive
proximity switch with illuminated display, eliminating the problems
present in the prior art and using, in particular, an advantageous
combination of the capacitive proximity switch and the illuminated
display.
[0006] This object is achieved in one embodiment by a sensor
element device having the features as claimed herein. Advantageous
and preferred embodiments of the invention form the subject matter
of the further claims and are explained in greater detail in the
following text. The wording of the claims is made into part of the
substance of the description by express reference.
[0007] The sensor element device has an upper side for contacting
the underside of an operating panel of the operating device. The
sensor element device also has an illuminated display with a frame
body, in particular a light element with a frame, with a lighting
direction towards the underside of the operating panel. In
accordance with an embodiment of the invention, the illuminated
display is designed as a sensor element device or forms a part of
the sensor element device, to which end the sensor element is
electrically conductive at least on its side or upper side facing
the operating panel, thereby forming a planar sensor element for
the capacitive proximity switch. This sensor element is then in
contact with the underside of the operating panel, similar to how
the surrounding metal frame does this in the aforementioned EP 1
030 536 A1, for example. Furthermore, the illuminated display is
mounted on a component carrier by means of a voluminous
spatial-shape-variable and/or elastic layer of electrically
conductive material. This material layer thus provides as a first
function an elastic or flexible pressing of the illuminated
display, and hence of the sensor element, against the underside of
the operating panel. Furthermore, the illuminated display has an
electrically conductive connection of its upper side to its
underside, for establishing contact with the material layer. The
sensor element is therefore connected via this material layer, as a
second function, to an electrical port on the component carrier,
which can lead to a control and/or evaluation unit or to a general
control unit.
[0008] The material layer for the sensor element device thus
performs two functions, i.e., first flexibly pressing of the sensor
element against the underside of the operating panel to achieve
electrically and technically readily controllable and defined
conditions, and second forming at least a part of the electrical
contacting or electrical connection to the sensor element,
preferably the entire electrical connection.
[0009] In another embodiment of the invention, the sensor element
on the upper side of the illuminated display can be designed at
least in a surrounding and frame-like manner, possibly also
full-surface. In the case of a sufficiently wide version with a few
millimeters of frame width, this is sufficient for a capacitive
proximity switch. The sensor element can, in accordance with
another embodiment of the invention, advantageously cover the
entire surface of the illuminated display or can be formed by the
entire surface of the illuminated display. There are several
possibilities to do so, which are described below. It must then of
course also be ensured that if the illuminated display has to be
translucent in the central area or to emit light, the sensor
element does not have a negative impact on this light emission.
[0010] In an alternative embodiment of the invention, the sensor
element can also be designed in a frame-like and surrounding manner
with a recess advantageously arranged in the middle. The recess can
either be smaller than a display symbol of the illuminated display,
particularly in the case of a diffuse light guide material, or
advantageously at least as large as a display symbol of the
illuminated display. The sensor element can thus be designed opaque
without problem and a translucent portion is no longer
required.
[0011] The sensor element is advantageously in planar contact with
the underside of the operating panel for the best possible function
as a capacitive proximity switch. In particular, it is in contact
by its entire surface, i.e., in the case of a frame-like design by
this frame area, alternatively by its entire area.
[0012] In another embodiment of the invention, the electrically
conductive connection of the sensor element on the upper side of
the illuminated display to the underside can be a conductive
lacquer, i.e., an electrically conductive lacquer, alternatively an
electrically conductive coating. In this case, areas can be
provided on the top of the illuminated display, at least in the
form of the previously described sensor element, i.e., where the
upper side of the illuminated display or the sensor element is in
contact with the underside of the operating panel. The conductive
lacquer can extend from the rim of the illuminated display to its
lower area or to its underside, i.e., to a contact or touch surface
with the material layer. In this way electrical contact is
established.
[0013] In a further embodiment of the invention, a previously
described conductive lacquer can be translucent, advantageously
substantially transparent. It can then cover substantially the
entire surface of the illuminated display, as already described
above.
[0014] Alternatively, the conductive lacquer can be opaque, for
example a silver lacquer. It can then cover, as previously
described, a surrounding frame-like area of the upper side of the
illuminated display and leave the illuminated area in the center
free. An opaque portion at the side of the illuminated display is
not disruptive, since no illumination is usually required there
anyway. It is possible that illumination at the side can be
prevented solely by an opaque conductive lacquer of this type, for
example when the material of the entire element is translucent. The
application of a conductive lacquer of this type can be achieved
for example by dipping, spraying or printing. Removal of the opaque
conductive lacquer in the form of the illuminated symbol to be
displayed can for example be achieved in line with DE 10 2004 040
998 A1 or in line DE 10 2009 036 161 A1, to which explicit
reference is made in this respect. Removal by laser is regarded as
particularly advantageous.
[0015] Alternatively to the provision of a conductive lacquer, both
as the sensor element and as the electrical connection from said
sensor element to a material layer, it can be provided that the
illuminated display itself can be made at least partially, and
advantageously completely, from electrically conductive material.
This material can then form both the sensor element on the upper
side of the illuminated display and the described electrically
conductive connection on the material layer. This can
advantageously be made as a surrounding frame section of
electrically conductive plastic surrounding a light guide body made
of translucent material. This light guide body can, for example,
also be already designed in symbol form for the required
illuminated display. A light guide body of this type does not need
to be electrically conductive, since a sensor element of frame-like
design for the capacitive proximity switch is regarded as
sufficient and hence the expenditure for the translucent plastic
remains lower. It may also be possible to dispense completely with
such a light guide body and only to provide a corresponding recess
or lead-through as a light passageway. The electrically conductive
plastic of the illuminated display thus forms with its upper side
the capacitive sensor element and with its underside or lower area
the electrical contact with the material layer. The expensive
application of a conductive lacquer can thus be dispensed with.
[0016] Alternatively to a conductive lacquer on the upper side of
the illuminated display as the capacitive sensor element, an
alternative electrically conductive coating could be applied,
possibly even as a metallic coating or thin metal sheet or thin
metal foil. The latter are then advantageously glued on to prevent
assembly problems, where an electrically conductive adhesive can
also be advantageous for the gluing step. In yet another embodiment
of the invention, the illuminated display can comprise an
electrically conductive metal part with a recess in symbol form,
for example of thick sheet metal as a stamping.
[0017] The frame body or the illuminated display as a function unit
can be designed block-like. The form and above all the design of
the upper side for the sensor element can also be round, oval,
triangular or polygonal.
[0018] The illuminated display can be, for example, designed as a
seven-segment display with a frame body and with corresponding
light guide bodies of translucent material or light passageways,
advantageously seven in number. A light source or an illuminant is
then provided for each light guide body. The material between the
light passageways is then advantageously the same as that for the
frame body.
[0019] In a further embodiment of the invention, the illuminated
display is not only simply placed onto the material layer and
fastened or positioned where possible by a positive connection, but
an electrically conductive bond can also be provided. As a result,
the illuminated display and the material layer can be formed with
prior gluing as a single component, which can then easily be fitted
onto the component carrier. The material layer can also be fastened
in similar form on the component carrier with an electrically
conductive bond.
[0020] The material layer can advantageously comprise electrically
conductive, elastic foamed plastic, described for example in the
above EP 859 467 A2 (also published as U.S. Pat. No. 5,917,165).
The height of the material layer can be a few millimeters,
preferably between 1 mm and 5 mm, and in particular it can be
between 3 mm and 4 mm, hence assuring a sufficient spring
deflection of 1 or 2 mm.
[0021] The material layer advantageously has a cutout into which an
illuminant for the illuminated display can be arranged. It is
particularly advantageous when this is an LED. A cutout like this
can be provided in the center so that the material layer can be
designed as a surrounding frame. It can be opaque towards the side,
so that unwelcome light towards the side and outwards, i.e., not
just on the upper side of the illuminated display, can be
avoided.
[0022] These and further features can be gathered not only from the
claims, but also from the description and the drawings, where the
individual features, both singly and severally in the form of
sub-combinations, can be implemented in various embodiments of the
invention and in other fields and can represent advantageous and
independently protectable designs for which protection is claimed
here. The subdivision of the application into individual sections
and subheadings in no way restricts the general validity of the
statements made there under.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Embodiments of the invention are shown schematically in the
drawings and described in greater detail in the following. The
drawings show in:
[0024] FIG. 1 a plan view of a sensor element device in accordance
with the invention in an oblique view, having an illuminated
display together with a symbol fastened on an elastic material
layer,
[0025] FIG. 2 the sensor element device from FIG. 1 in an oblique
view of the underside,
[0026] FIG. 3 the sensor element device from FIG. 1 in the
installed state in an operating device between the component
carrier and the operating panel, and
[0027] FIG. 4 a section through a slightly modified sensor element
device similar to FIG. 2.
DETAILED DESCRIPTION
[0028] FIG. 1 shows in an oblique plan view a sensor element device
11 having a block-like illuminated display 13 made of plastic. The
illuminated display 13 comprises a frame body 14 made of opaque
plastic. Instead of plastic, a conductive metal part can also be
used. A light guide body 16 in symbol form is injection-moulded
into the frame body 14 to create a plus sign. This is easily
possible in two-component injection moulding. Alternatively to a
light guide body, the entire part can also consist of translucent
plastic and an opaque conductive lacquer can be applied to the
upper side to create the symbol using the symbol cutout.
[0029] As shown by the hatching of the frame body 14, the frame
body is covered by an electrically conductive lacquer, in
particular on the upper side 15 and on the other sides and the
underside. A conductive lacquer like this can be designed either as
the previously described silver lacquer and opaque, while leaving
free the light guide body 16 or symbol, or translucent, so that the
entire upper side 15, including over the light guide body 16, is
lacquered and coated by the conductive lacquer.
[0030] The illuminated display 13 is fastened on a thick material
layer 19 that is very thick or almost block-like and comprises the
above material. Its design can also be seen from the view in FIG.
2. The material layer 19 has a central recess 20 passing through it
completely. An illuminant or an LED can be arranged therein, as
explained in greater detail in the following, and radiating from
underneath into the light guide body 16 and thus illuminating its
symbol form. A connection of the illuminated display 13 and the
material layer 19 can be achieved by an electrically conductive
adhesive. This enables both electrical contacting and a mechanical
connection of the two parts to form one structural unit.
[0031] FIG. 3 shows an operating device 22 where a sensor element
device 11 in accordance with FIGS. 1 and 2 is installed. A large
contact panel 25 with feed line 26 is provided on a component
carrier 24, advantageously a standard PCB. The sensor element
device 11 is placed thereon with an underside of the material layer
19 and held mechanically. It is advantageously glued on with
conductive adhesive.
[0032] The illuminated display 13 and the sensor element device 11
contact with the upper side 15 the underside 29 of the operating
panel 28. The upper side 15 shown hatched in FIG. 1 here forms a
capacitive sensor element with a large area thus contacting the
underside 29, as is usual in the case of a capacitive proximity
switch. This sensor element of the upper side 15 is linked via the
electrically conductive coating over the sides of the frame body 14
to its underside and there in turn connected to the electrically
conductive material layer 19. The material layer in turn is
connected to a control unit by the connection with the contact
panel 25 and the feed line 26. As a result, a planar sensor element
is achieved as the upper side 15 against the underside 29 of the
operating panel 28. The latter operates in the usual way by
detection of the placing of an operator's finger above the sensor
element device 11 or the upper side 15.
[0033] It is therefore possible with the invention to keep the
illuminated display 13 with the sensor element as the upper side 15
pressed against the underside 29 of the operating panel 28 thanks
to the springy or elastic yielding properties of the material layer
19. In this way, both possible movements and height tolerances or
assembly tolerances can be equalized. There is always a defined
contact of the upper side 15 to the underside 29. Furthermore, it
is possible due to the electrically conductive coating and to the
electrically conductive material layer 19 to achieve a connection
to the sensor element as the upper side 15.
[0034] An alternative design of the sensor element device 11 is
shown in FIG. 4, where no electrically conductive coating of the
illuminated display 113 is provided, and the frame body 114
comprises electrically conductive plastic. It also does not have to
be designed translucent or specifically non-translucent. It
encloses a light guide body 116, which does not however have to be
electrically conductive. An upper side 115 of the frame body 114 is
sufficient as a surrounding area for again forming a capacitive
sensor element.
[0035] The illuminated display 113 rests with an underside of the
frame body 114 on an upper side of a material layer 119. The latter
is in turn designed in accordance with the previous figures, i.e.,
electrically conductive and elastic. However, the frame body 114
has here a ring-like flange 117 projecting at the underside for
improving the bond between the two parts and engaging from above
into a central recess 120 of the material layer 119. In this way
precise centering or assignment is determined. Furthermore, a
certain holding effect is achieved. It may thus be possible to
dispense with gluing of the two parts, this being regarded as
advantageous both for mechanical holding and for an electrically
conductive connection using conductive adhesive.
[0036] Furthermore, FIG. 4 also shows an LED 131 as the illuminant,
extending into the central recess 120 and radiating from underneath
into the light guide body 116 and out at the top with its symbol
form or any required form. An LED of this type can also be provided
in the operating device 22 in accordance with FIG. 3 in the center
of the contact panel 25 and electrical LED connections can be
connected by through-contacts inside the surface of the contact
panel 25.
[0037] An advantage during processing and manufacture of the
operating device is therefore that the illuminated display together
with the material layer of the stated plastic can be made
beforehand as one structural unit or sensor element device. This
means that component fitting is very easy. For example, an adhesive
tape ensuring electrical conductivity is provided on the underside
of the material layer after connection of the two parts to form one
structural unit. This structural unit can thus be fitted with an
automatic surface mounted device ("SMD") machine onto component
carriers or PCBs. Furthermore, a higher component density can be
achieved in this way, since compared with solutions known from EP 1
030 536 A1, for example, no sensor element devices are necessary
which are larger at the side than the illuminated display
itself.
* * * * *